NAME¶

Mail::SpamAssassin::Plugin::OLEVBMacro - scan Office documents for evidence of OLE Macros or other exploits

SYNOPSIS¶

  loadplugin Mail::SpamAssassin::Plugin::OLEVBMacro
  ifplugin Mail::SpamAssassin::Plugin::OLEVBMacro
    body     OLEMACRO eval:check_olemacro()
    describe OLEMACRO Attachment has an Office Macro
    body     OLEOBJ eval:check_oleobject()
    describe OLEOBJ Attachment has an Ole Object
    body     OLERTF eval:check_olertfobject()
    describe OLERTF Attachment has an Ole Rtf Object
    body     OLEMACRO_MALICE eval:check_olemacro_malice()
    describe OLEMACRO_MALICE Potentially malicious Office Macro
    body     OLEMACRO_ENCRYPTED eval:check_olemacro_encrypted()
    describe OLEMACRO_ENCRYPTED Has an Office doc that is encrypted
    body     OLEMACRO_RENAME eval:check_olemacro_renamed()
    describe OLEMACRO_RENAME Has an Office doc that has been renamed
    body     OLEMACRO_ZIP_PW eval:check_olemacro_zip_password()
    describe OLEMACRO_ZIP_PW Has an Office doc that is password protected in a zip
    body     OLEMACRO_CSV eval:check_olemacro_csv()
    describe OLEMACRO_CSV Malicious csv file that tries to exec cmd.exe detected
    body     OLEMACRO_DOWNLOAD_EXE eval:check_olemacro_download_exe()
    describe OLEMACRO_DOWNLOAD_EXE Malicious code inside the Office doc that tries to download a .exe file detected
    body     OLEMACRO_URI_TARGET eval:check_olemacro_redirect_uri()
    describe OLEMACRO_URI_TARGET Uri inside an Office doc
    body     OLEMACRO_MHTML_TARGET eval:check_olemacro_mhtml_uri()
    describe OLEMACRO_MHTML_TARGET Exploitable mhtml uri inside an Office doc
  endif

DESCRIPTION¶

This plugin detects OLE Macros or other exploits inside Office documents attached to emails. It can detect documents inside zip files as well as encrypted documents.

REQUIREMENT¶

This plugin requires Archive::Zip and IO::String perl modules.

USER PREFERENCES¶

The following options can be used in both site-wide ("local.cf") and user-specific ("user_prefs") configuration files to customize how the module handles attached documents

olemacro_num_mime (default: 5)

Configure the maximum number of matching MIME parts (attachments) the plugin will scan.

olemacro_num_zip (default: 8)

Configure the maximum number of matching files inside the zip to scan. To disable zip scanning, set 0.

olemacro_zip_depth (default: 2)

Depth to recurse within zip files.

olemacro_extended_scan ( 0 | 1 ) (default: 0)

Scan all files for potential office files and/or macros, the "olemacro_skip_exts" parameter will still be honored. This parameter is off by default, this option is needed only to run "eval:check_olemacro_renamed" rule. If this is turned on consider adjusting values for "olemacro_num_mime" and "olemacro_num_zip" and prepare for more CPU overhead.

olemacro_prefer_contentdisposition ( 0 | 1 ) (default: 1)

Choose if the content-disposition header filename be preferred if ambiguity is encountered whilst trying to get filename.

olemacro_max_file (default: 1024000)

Limit the amount of bytes that the plugin will decode and scan from the MIME objects (attachments).

olemacro_exts (default: (?:doc|docx|dot|pot|ppa|pps|ppt|rtf|sldm|xl|xla|xls|xlsx|xlt|xltx|xslb)$)

Set the case-insensitive regexp used to configure the extensions the plugin targets for macro scanning.

olemacro_macro_exts (default: (?:docm|dotm|ppam|potm|ppst|ppsm|pptm|sldm|xlm|xlam|xlsb|xlsm|xltm|xps)$)

Set the case-insensitive regexp used to configure the extensions the plugin treats as containing a macro.

olemacro_skip_exts (default: (?:dotx|potx|ppsx|pptx|sldx)$)

Set the case-insensitive regexp used to configure extensions for the plugin to skip entirely, these should only be guaranteed macro free files.

olemacro_skip_ctypes (default: ^(?:text\/))

Set the case-insensitive regexp used to configure content types for the plugin to skip entirely, these should only be guaranteed macro free.

olemacro_zips (default: (?:zip)$)

Set the case-insensitive regexp used to configure extensions for the plugin to target as zip files, files listed in configs above are also tested for zip.

olemacro_download_marker (default: (?:cmd(?:\.exe)? \/c ms\^h\^ta ht\^tps?:\/\^\/))

Set the case-insensitive regexp used to match the script used to download files from the Office document.